Wanting to get started with an LCD Touch Screen
groggory
Posts: 205
Honestly, I'm a bit overwhelmed by all the touch screen threads going on here. I've read every one I can get my hands on and I don't know what path I should start on.
Here's what I want:
~3-4" LCD that can be seen in daylight
Single Touch, resistive (I'll be putting a protective plastic film over it)
An interface board that is open source so that I can later integrate it onto my PCB design (for space saving)
Code to run the thing, lol
Low cost parts as much as possible
I'm planning on using this as a control interface for a program I'm building. So basically, it'll throw some statistics to the screen and will have a few buttons on the screen. Pretty simple stuff.
I've thought about using a multi-line LCD screen and some buttons for control...but having a touch screen would be so slick and if the price is where I hope it is...roughly the same cost once you factor in all the other buttons and stuff I need to support them on a nice case.
Thank you for the help. I'm usually a self-solver, but I'm just overwhelmed here.
Here's what I want:
~3-4" LCD that can be seen in daylight
Single Touch, resistive (I'll be putting a protective plastic film over it)
An interface board that is open source so that I can later integrate it onto my PCB design (for space saving)
Code to run the thing, lol
Low cost parts as much as possible
I'm planning on using this as a control interface for a program I'm building. So basically, it'll throw some statistics to the screen and will have a few buttons on the screen. Pretty simple stuff.
I've thought about using a multi-line LCD screen and some buttons for control...but having a touch screen would be so slick and if the price is where I hope it is...roughly the same cost once you factor in all the other buttons and stuff I need to support them on a nice case.
Thank you for the help. I'm usually a self-solver, but I'm just overwhelmed here.
Comments
p8x32A-d40 @ 80mhz
2- 512k Sram with fast address bus
ports for 2 standard 40-pin LCDs *tested with 3.2" SSD1289 and 2.4" ILI9325, should also work with SSD1963
Stereo audio output.
2-ch 8 bit ADC.
Expansion boards with tv, vga, keyboard, rs323, RTC, and more
about 30 pins free *pins are accessed in groups*
lots of code, with more on the way. Able to draw BMPs from SD card, many fonts, all open source.
A bit more about your application would help. What external devices are you interfacing with?
There were meant for units like GPS, so they work well outside...
If you want capacitive touch, we've just figured out how to do that with the Newhaven 4.3" touchscreens too...
I've been doing a lot of reading on your site as of late.
So for $5 for a used LCD + $19.99 for a breakout board I can get started on this path? Sounds really cool. I'll send you an email today. Is the code on your page the most current code for that display?
http://www.rayslogic.com/Propeller/Products/PSB/PSB_Display.htm#Breakout_Boards
As far as the capacitive touch, is that touch or multi-touch?
What model Newhaven screen are you referring to? The NHD-4.3-480272MF-ATXI#-CTP-1
My main thing I need is 3 RS232 ports, a RTC, an SD card, and a couple I/O. That part isn't a big deal. I have a custom PCB that I've developed that deals with that. Still a work in progress, but I have that part under control.
I just need to decide on what display to go with and make sure the display with make sense if this product gets built in quantity for resale.
Use it to display the outpot of a D/A. Has several 'buttons' on-screen for specific touch points. Two cursors to measure time between events. Long battery life, has SC card socket.
Wow, that looks exciting.
I'm stoked to move from the world of serial terminals and buttons everywhere to a nice, easy to customize, touch LCD
Right now, it's a little cumbersome to connect (you'd need jumper wires), but I do sell a little $3 connector breakout that makes it easier...
The resitive one is easier, just plug it in...
Email sent. Let's get this party rolling
Actually that is the bit that has had averagejoe and me stumped for months *grin*.
Put in all those extras and there are less pins. Less pins = slower updates to the display. So we initially got it working with less pins (8 bit mode) but it was too slow. With full color touchscreens, a display is 240x320x2 bytes which is a lot more than the propeller memory. So for fast updates - moving sprites around, icons, refreshing screens etc you need to be able to dump data from ram to the display very fast. The somewhat strange design averagejoe and I have, with all those extra chips, is because we started with the core of the design a fast ram to display interface, and then added the propeller later.
For more ports and I/O we have gone for a second board with another propeller on it.
Having said all that, if the display is not being changed much you can move things from the SD card to the display. (ballpark, about 2 secs to draw a display from an SD card, and about 0.03 seconds from external ram). I'm using these displays http://www.ebay.com.au/itm/2-4-TFT-LCD-Module-Display-Touch-Panel-PCB-adapter-SD-Card-Cage-320-240-New-/270973667234?pt=LH_DefaultDomain_0&hash=item3f174a07a2 $13.95 with free shipping and averagejoe is using one a bit larger
Here are some tips for deciding between the 3.5 and 4.3" products from Rayslogic.com:
Most people prefer the 4.3" displays because it has higher resolution and larger size.
Also, the driver board is simpler than the 3.5" version.
Rayslogic.com has "like new" and "used" versions at low cost.
You can also connect the same LCD to the new Rayslogic.com DVI graphics shield with the 4.3" plugin adapter,
in case you one day need 24-bit color graphics.
But, the 3.5" display also has some advantages...
It is smaller and so uses less power.
The screen resolution is smaller so it uses less Propeller resources.
The small physical size may be needed for small devices.
The new PTP2 driver board increases color depth from 6 to 8 bits and so can show more colors than the 4.3" version.
Rayslogic.com sells "new" displays at a very low cost.
BTW: Both of these boards have the same touchscreen chip that also has
analog inputs you can use for measuring things like battery voltage. It
also can tell you the temperature. The PTP2 board also has a few
expanded digital I/O pins on the same connector as these analog ADC
inputs.
It seems to me that Rayman's setups are a simpler setup that can easily 'glue' onto any project for relatively low cost.
The Touchburger is more of a full, integrated solution...but also keeps the ability to add onto it. The Touchburger has significantly better performance at the expense of more IO, more supporting chips, and more COGs necessary to get it running.
...
My preference: I bought both. The touch burger from Joe and the PTP2 (gadget gangster usb) w/ 3.5" display from Ray.
Hats off to all the developers of this stuff! Everyone is awesome and doing great things for the community and this platform
Ray has quite a few interesting goodies, great for gluing into projects like as you said. I must order a DVI Graphics shield some day